n.

1. 昏睡；瞌睡
   Several hours after the surgery, she was still in her lethargy.

   手術過後幾小時，她仍然昏睡不醒。

2. 不活潑；無生氣
   The bird's lethargy in the morning was unusual.

   這隻鳥在早上就無生氣，很不尋常。

n.

1. a lack of energy and enthusiasm.
2. Medicine  a pathological state of sleepiness or deep unresponsiveness.